What do the following two equations represent? $2x-2y = 5$ $6x+6y = 4$
Solution: Putting the first equation in $y = mx + b$ form gives: $2x-2y = 5$ $-2y = -2x+5$ $y = 1x - \dfrac{5}{2}$ Putting the second equation in $y = mx + b$ form gives: $6x+6y = 4$ $6y = -6x+4$ $y = -1x + \dfrac{2}{3}$ The slopes are negative inverses of each other, so the lines are perpendicular.